One of the most effective ways of raising and lowering a screw operated vehicle lifting jack is by use of a crank. A crank provides a desired mechanical advantage for turning the screw and also results in ease of operation as a consequence of the simple cranking action.
Cranks are however, undesirably large and present a stowage problem in view of their bulky nature. Additionally, cranks have usually been provided as items separate from the jack. This has often resulted in loss of the crank.
The present invention provides the combination of a lifting jack with an integral stowable crank. The crank includes some features which have been proposed in the past but not included in a single combination. For example, the crank of the present invention is foldable. It is desirable to have a foldable crank in order that the crank is long enough to fit easily under a vehicle while at the same time being foldable for stowage. Foldable or telescoping cranks have been suggested in U.S. Pat. Nos. 1,326,451 issued Dec. 30, 1919 to H. S. Jillson et al, 1,286,161 issued Nov. 26, 1918 to A. F. Wagner, 2,557,465 issued June 19, 1951 to J. C. Rauscher, Sr., 1,193,126 issued Aug. 1, 1916 to E. M. Cumings and 1,361,593 issued Dec. 7, 1920 to A. B. Lang. However, these patents do not teach means for permanently connecting the crank to the lifting jack while at the same time permitting the crank to be swung into the jack for storage purposes.
It is also desired, for maximum turning torque, that the crank turning arm be in alignment with the jack screw and be connected to the jack screw by means of a universal-type joint connection to permit tilting of the crank away from the ground to avoid hitting the ground as the crank is turned and permitting the user to adopt a comfortable kneeling or bending position while manipulating the lifting jack. The desirability of this type of connection is taught in U.S. Pat. Nos. 1,468,771 issued Sept. 25, 1923 to E. E. Arnold, 1,901,915 issued Mar. 21, 1933 to M. H. Loughridge and 2,479,362 issued Aug. 16, 1984 to W. Jackson. However, again, the provision of a foldable crank swingable onto the jack for stowage is not suggested.
In accordance with the present invention, a combination as above described having the following four desirable features is provided:
1. A foldable crank.
2. Means permitting the folded crank to be swung into the jack for storage.
3. A permanent connection of the crank to the jack.
4. A universal-type connection of the crank to the jack.